I don't think that's the issue per say, although I'm sure it's still a hurdle to overcome. There's a lot of health and safety challenges with anything permanent and many implications that aren't obvious to those looking in from the outside.
Nobody is saying we can't do it? But people throw it out as a solution when it took Accrington well over a year to get to where they are now. Nothing happens in places like sports stadiums without lots of planning and safety measures.
There are plenty of options like that for a permanent structure but we cant use that under the current licence rules. Need something that can be assembled/dissembled every matchday That might change in the future.
I would imagine whatever budget the club has for fan experience improvement this summer has just been reduced by £22,250.